The option will go live with an upgrade of Office 365 this summer

Microsoft offered more details on Tuesday about its plans to integrate SharePoint and Yammer, saying it'll give Office 365 customers the option of replacing SharePoint Online's activity-stream component with Yammer's.

Without committing to a specific date, Microsoft said it would provide this option during the summer. In the same timeframe, it will offer a Yammer application that will let users embed a Yammer group feed into a SharePoint site, Microsoft said. This Yammer application, which will be available on the SharePoint app store, will work both with SharePoint Online and with SharePoint 2013 servers installed on customer premises.

Later in the year, the integration will deepen with a single sign-on process for both products, and Yammer will be included in the Office 365 interface. Yammer will also gain integration with Office Web Apps, the browser-based version of the Office productivity suite.

In 2014, Office 365 customers can expect integration between Yammer and other Office 365 components beyond SharePoint, such as Lync and Exchange.

On Tuesday, Microsoft also reiterated that Yammer represents the future of the company's push for adding ESN (enterprise social networking) features to its products. However, Microsoft also said it recognizes that some enterprises will be uncomfortable adopting Yammer, because it's a multi-tenant cloud service, so it will continue to offer and support SharePoint on premises.

At its SharePoint Conference in November of last year, Microsoft said in a press release it planned to integrate Yammer and SharePoint in the areas of "unified identity, integrated document management and feed aggregation." However, Microsoft hadn't provided an update on those plans until today.

Microsoft bundles Yammer with some enterprise editions of Office 365, the cloud collaboration and email suite that includes SharePoint Online, Exchange Online, Lync Online and other components.